The influence of probiotics on genital high-risk human papilloma virus clearance and quality of cervical smear: a randomized placebo-controlled trial

BackgroundProbiotics has been shown to be effective in reducing vaginal colonization of pathogenic organisms. The aim of this study was to investigate the influence of probiotic strains Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 on genital high-risk human papilloma virus (HR-HPV) clearance and quality of cervical smear.MethodsThis was a randomized, double-blinded, placebo-controlled trial. Women with genital HR-HPV infection were randomized into study and control groups. A probiotic or placebo preparation was administered orally (one capsule daily) until negative HR-HPV testing. A cervical smear and HR-HPV tests were performed at the beginning of the study and every 3months thereafter until a negative result was obtained.ResultsA total of 121 women with genital HR-HPV infection were enrolled (62 in the study group and 59 in the control group). There was no significant difference in HR-HPV clearance rate between the two groups (58.1% vs. 54.2%). The only factor predicting HR-HPV clearance was a lower initial viral load (HR 3.214; 95% CI: 1.398, 7.392; p=0.006). Twenty-two women had a mildly abnormal initial cervical smear and nine had an unsatisfactory smear. At 6months follow-up, both mildly abnormal cervical smear and unsatisfactory smear rates had decreased significantly in the study group compared to the control group (p=0.017 and 0.027).ConclusionsThe application of probiotic strains Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 did not influence genital HR-HPV clearance, but may have decreased the rates of mildly abnormal and unsatisfactory cervical smears.